New York Yankees right fielder Aaron Judge hits a two-run home run during the fifth inning of a baseball game against the Chicago White Sox, Monday, April 17, 2017, at Yankee Stadium in New York. (AP Photo/Bill Kostroun)(Photo: Bill Kostroun, AP)

Managers are usually loathe to over-emphasize any series in April and for good reason: It’s awfully early for a litmus test. But what fun is that? Why not ride shotgun with the Mets and Yankees for the next 10 days, when there’ll be plenty of first-month data to harvest. It’ll be a stretch of Nationals, Red Sox and Nationals, after which we’ll all be wiser, even if the drama isn’t supposed to count for much.

But hold on, there’s more here than just hype. For the next two weekends the Mets will be squaring off against their division rival who beat them 12 of 19 times last year. The timing couldn’t be worse for the Mets, who’ve lost 5-of-6 and are once again being staggered by injuries. Yoenis Cespedes was the latest to go down, suffering a hamstring injury in Thursday’s 6-4 defeat to Philadelphia. The slugger will undergo an MRI, prompting Terry Collins to darkly note, “Our trainer’s room in filling up in a hurry.”

The Mets were an advertisement in tough talk in spring training; they owned the universe in March. But less a month later there’s a creeping sense the path to the playoffs could be booby-trapped by teams that are unimpressed with the Mets’ self-promotion. Forget the Nationals; the Mets are just 8-8 against the rest of what was supposed to be a mediocre East. They couldn’t even take a series at home against the Phillies, which is indefensible.

The Yankees, meanwhile, are moving in the opposite direction of the Mets, looking for a breakout of their own on Yawkey Way next week.

The Yankees finished up a 9-1 home stand with an iron belief that this was only the beginning of a summer-long ambush - not just of the Red Sox but the AL as a whole. Here’s their first shot to deliver that message.

Of course, there’s still five-plus months to go. Plenty can and will change. But there five specific match-ups and/or questions that’ll determine the course of the next ten days. And with it, they’ll allow for a more informative look at who the Mets and Yankees really are and where they’re headed.

CC Sabathia at Fenway: The big man hasn’t been particularly successful on the Sox’ home turf, where he has a career 5.48 ERA and 1.597 WHIP. But Sabathia is in the process of remaking himself this year, all but perfect in using his slider on both sides of the plate. The Sox have hit the fewest HRs in the league, but they’re third in OPS and more dangerous than the Cardinals, who Sabathia beat last week, and the Pirates, who he’ll face on Saturday. The Wall is waiting for the veteran left-hander who’s traded velocity for finesse.

How fast can Jeurys Familia help? Just how desperate are the Mets for relief help? One major league executive wondered out loud if Sandy Alderson might just trade Jay Bruce – “always, always sell high” – as a way to find bullpen reinforcements and a prospect or two.

That’s not going to happen, not with Jose Reyes and Curtis Granderson struggling. The Mets need all the offense they can get. But the late innings are a legitimate problem for the Mets. Familia appeared in a non-save situation on Thursday, and although he held the Phillies scoreless, Collins said the closer looked, “rusty to say the least.”

The Mets can take some consolation in the Nationals’ bullpen crisis: their relievers have a 6.08 ERA, including 10 home runs allowed in 40 innings. But that doesn't diminish the Mets’ need for extended outings this weekend from Jacob DeGrom, Matt Harvey and Zack Wheeler, thus limiting the exposure of the middle-relief crew. The organization has to assume Familia is returning from a 15-game suspension with his sinking, two-seam fastball intact as well as his confidence. The Mets don’t want to contemplate the alternative.

Will Reyes start hitting? Ever? Time may be running out on the veteran infielder, whose average stands at .105 after another unproductive game (1-for-4) on Thursday. If Reyes continues to under-perform, particularly against the Nationals, don’t discount the possibility of an imminent release. Remember, despite the club’s obvious affection for him, Reyes is owed only $535,000 for 2017. That’s not an insurmountable salary to throw overboard if (or when) the Mets decide he’s lost his skills at 33.

Can Aaron Judge hit Chris Sale? This is really what the mini-renaissance will boil down to. Judge represents all that is young and hopeful about this surprising Yankees’ lineup. He is exceeding everyone’s expectations, including his own, with a deadly mix of power and uncharacteristic strike zone discipline. Sale will provide the ultimate test.

The Sox’ ace has allowed just three runs over 29.2 innings, while striking out 42. batting .129 against him. Sale’s staccato delivery and low three-quarters release point is poison even for mature hitters. How Judge fares will serve as a microcosm for the rest of the lineup. This is a matchup worth waiting for.

Can Terry Collins Find That Extra Gear? The manager has tried to play to his strength, keeping the Mets upbeat and forward-directed in the midst of a wobbly start. But you could hear his frustration on Thursday. The Mets didn’t expect to be chasing the Nationals this quickly or to be mired at .500.

Losing three of four to the Marlins last weekend was a psychological setback felt throughout clubhouse and in the manager’s office as well. Even worse, the Mets dropped 2-of-3 to the Phillies at Citi, including the rubber game with Noah Syndergaard on the mound. It’s unforgivable for a team that considers itself October-bound.

Familia’s return should help, but Collins’ biggest challenge will be keeping the Mets from collapsing against the Nats, the last team they need to see right now.